Search Results (7)

Biochar has gained significant attention for its potential in carbon sequestration, soil health improvement, and crop production sustainability. However, the existing studies predominantly focus on short-term experiments conducted in acidic or neutral soils. This study investigates the long-term effects of biochar application in a calcaric cambisol in a field experiment with four treatments: CK (no fertilizer or biochar), B (only biochar), NPK (chemical fertilizer), and NPKB (combination of chemical fertilizer and biochar). This study assessed soil organic carbon (SOC), sorghum yield, soil bacteria, plant nutrient accumulation in 2020 and 2022, and soil chemical properties after 12 years of consecutive application in 2022. The results revealed a significant increase in SOC due to biochar application in both 2020 and 2022 compared to the treatments without biochar. The 12-year biochar application also significantly enhanced soil total nitrogen (N), available phosphorus (P), and available potassium (K), irrespective of chemical fertilizer application. Notably, sorghum plant N and P accumulation remained unaffected by biochar, and plant N accumulation induced by NPKB was even lower than that of the NPK treatment in 2022. Furthermore, soil bacterial diversity and composition, as well as sorghum yield, showed no significant alterations due to biochar application in both years, despite increased soil nutrient content. These findings affirmed the benefits of carbon accumulation through long-term biochar application in calcaric cambisols, but the positive effects on crop production were found to be negligible. Full article

Ethnopedology offers a unique opportunity to recognize and highlight invaluable local soil knowledge (LSK). We aimed to classify three soil profiles in a Brazilian irrigated district with salt-affected soils based on smallholder farmers’ LSK and scientific knowledge. The study occurred in the Baixo-Açu irrigation district in Brazil’s semi-arid region. Three soil profiles were characterized by researchers (etic approach) and farmers (emic approach) in the following areas: P1 profile (area under banana cultivation), P2 profile (fallow area), and P3 profile (native forest area). Smallholder farmers identified the studied areas with salt problems based on the salt precipitation on the surface, changes in leaf color, and incidence of indicator plants of salinized areas. Researchers classified P1 profile as Pantohypereutric Calcaric Leptic Cambisol (Loamic, Humic), P2 as Pantohypereutric Calcaric Leptic Cambisol (Loamic, Humic), and P3 as Leptic Calcic Chernozem (Loamic). Smallholder farmers classified the P1 profile as “Terra de Salitre” (Salt Soil), the P2 profile as “Terra de Piçarro” (Saprolite Soil), and the P3 profile as “Terra Boa” (Good Soil). The results indicate that valuing local soil knowledge is effective and crucial for improved scientific research and land use, highlighting the importance of recognizing and utilizing their expertise and experience. Full article

Pesticide residues and heavy metal concentrations were determined in two depths (0–20 and 20–40 cm) of Chromic Cambisol in 69 vineyards in the Slovenian winegrowing region of the Karst. Similarly, pesticide residues and heavy metal concentrations were also determined in two depths of Calcaric Cambisol in 11 vineyards in the other Slovenian and Croatian winegrowing regions of Istria. The topsoil (0–20 cm) was analysed for the presence of 176 different pesticidal active substances using two multiresidue analytical methods: (a) gas chromatography coupled with mass spectrometry (GC/MS) and (b) liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Seven active substances (five fungicides and two insecticides) were detected in the soil samples. Their concentrations were compared with the maximum concentrations observed in the vineyards of the winegrowing regions of France, Italy, and Spain. In addition to pesticides, the soil samples were analysed for the presence of nine heavy metals commonly detected in vineyard soils. The concentrations of arsenic, cadmium, cobalt, chromium, copper, molybdenum, nickel, lead, and zinc were below the critical thresholds set by Slovenian legislation, with the exception of one soil sample in which the Cu concentration exceeded the critical threshold. Compared with the maximum concentrations measured in other vineyard soils in Spain, Italy, and France, the heavy metal concentrations in the vineyard soils of Karst and Istria were lower. Both the heavy metal concentrations and the residual concentrations of pesticidal active substances in the vineyard soils of the Karst and Istria regions were significantly lower than the concentrations that are occasionally discussed in the literature. Full article

Shallow landslides due to the soil saturation induced by intense rainfall events are very common in northern Italy, particularly in the Alps and Prealps. They are usually triggered during heavy rainstorms, causing severe damage to property, and sometimes causing casualties. A historical study and analysis of shallow landslides and mud-debris flows triggered by rainfall events in Lombardy was carried out for the period of 1911–2010, over an area of 14,019 km². In this study, intensity–duration rainfall thresholds have been defined using the frequentist approach, considering some pedological characteristics available in regional soil-related databases, such as the soil region, the textural class, and the dominant soil typological units (STU). The soil-based empirical rainfall thresholds obtained considering the soil regions of the study area were significantly different, with a lower threshold for landslide occurrence in the soil region M1 (Alps), where soils developed over siliceous parent material, with respect to the whole study area and the soil region M2 (Prealps), where soils developed over calcareous bedrocks. Furthermore, by considering textural classes, the curves were differentiated, with coarse-textured soils found more likely to triggerlandslides than fine soils. Finally, considering both texture and main soil groups, given the same rainfall duration, the rainfall amount and intensity needed to initiate a landslide increased in the following order: “coarse-skeletal” Cambisols < Umbrisols < Podzols < “fine” Cambisols. The results of this study highlighted the relevant role of pedological conditioning factors in differentiating the activation of rainfall-induced shallow landslides in a definite region. The information on soils can be used to define more precise rainfall–pedological thresholds than empirical thresholds based solely on meteorological conditions, even when they are locally defined. This knowledge is crucial for forecasting and preventing geo-hydrological processes and in developing better warning strategies to mitigate risks and to reduce socio-economic damage. Full article

Over the last decade, the two-phase centrifugation system for olive-oil extraction has become dominant in Slovenia. There are many suggestions for the exploitation of two-phase OMW, but among the suggested methods, direct spreading on agricultural land appears to be operationally simple and economically feasible for Slovenia. As there is little information available about two-phase OMW produced in the northern Mediterranean regions, the aim was to determine its composition and evaluate its use as a soil amendment in olive groves. This study shows that the characteristics of two-phase olive-mill waste produced in northern Mediterranean regions are similar to those of other countries. In addition, the calcareous characteristics of the Mediterranean soil can reduce its phytotoxic effects and might thus represent a natural system for olive-mill waste treatment. Phenolic compounds in the two-phase olive-mill waste are rapidly decomposed, and the soil has a high buffering capacity. Furthermore, the results of the soil analysis also showed some effects on the soil properties, such as a significant increase in K₂O and soil organic carbon. The combined application of two-phase olive-mill waste and mineral fertilizer to olive groves on eutric cambisols has positive effects on the physical, chemical and biochemical properties of the soil. Full article

Intensive tillage (CT) application in Mediterranean olive orchards has threatened soil quality and led to soil degradation. No tillage with bare soil (NT+H) has been considered as an alternative practice to this management system; however, there are discrepancies in the literature on the results of the application of this practice. Our main objective was to assess the impact of continuous tillage and zero tillage on soil aggregate stability, SOC and SON stocks. The study was conducted in a Mediterranean rainfed olive grove under semi-arid conditions in a Calcaric Cambisol, for 16 years evaluating complete soil profiles (0–120 cm depth). In the long-term, the management practices CT1 and NT+H significantly affected aggregate particle size by reducing the percentage of macro-aggregates (>250 μm) and promoting a higher number of micro-aggregates (<250 μm). Nevertheless, NT+H affected the Bw and BC horizons with the increase in the large macroaggregates (>2000 μm) percentage. In relation to these results, the soil structural stability indices showed a significant decrease in both Mean Weight Diameter (MWD) and Geometric Mean Diameter (GMD) values with losses of more than 50% with respect to the initial period (CT0) in the first two horizons. In the long term, both in CT1 and in NT+H, higher SOC concentrations were found in deep horizons showing a C redistribution in depth and important losses in TN values—while, in CT0, macroaggregates contained the highest CPC values, after the long-term both management practices (CT1 and NT+H) affected the C dynamics and were characterised by higher C pool in the microaggregates than in the macroaggregate fractions. Therefore, long-term NT+H and CT1 showed an SOC storage deterioration and increased susceptibility to decomposition, CO₂ emissions and fertility losses. This trend i.e., decreases in SOC stocks following NT, confirms previous studies on the subject and points to nutrient balance impacts. Full article

This study evaluated the effects of de-inking paper sludge (DPS) and sewage sludge (SS) application on soil properties, and durum wheat growth and yield. A pot experiment was performed on Calcaric cambisol (clCM) and Cromic Luvisol (coLV) soils. Three DPS rates (0, 30, and 60 Mg ha⁻¹) were studied with and without nitrogen fertilizer (280 kg NH₄NO₃ ha⁻¹). DPS was also mixed with SS at two rates (5 and 10 Mg ha⁻¹) to highlight the benefits of organic nitrogen compared to mineral nitrogen. DPS improved total organic carbon and nitrogen, mineral nitrogen, and soils cation exchange capacity, the 30% rate provided the greatest improvement in both soils. DPS increased grain and root P, K, Ca, and Mg contents in both soils. It also increased wheat straw N, P, Mg, and Ca for the same soil compared to the control. Mixed DPS treatments with nitrogen fertilizer enhanced grain yield by up to 38% and increased root biomass in the studied soils. Thus, DPS is a potential source of organic matter and a liming agent for acid soils when appropriate supplemental fertilizer is provided. Full article